The present invention generally relates to a machine for making emulsified or foam products from a mixture of a gas and a milk product capable of forming a foam and, more particularly, to a machine for making whipped cream.
It is generally well known that whipped cream can be manufactured by forcing air and cream simultaneously through a whipping means having such a large surface area of contact as to provide substantial agitation and intimate intermingling of the air and the cream.
According to the Japanese Patent Publication No. 46-36186, published on Oct. 23, 1971 and first applied for patent in Italy on Nov. 20, 1967 and July 8, 1968 under respective Italian patent applications Nos. 7442A/67 and 7152A/68, there is disclosed a whipped cream making machine which comprises a refrigerator-cooled cream tank and an emulsifying or whipping barrel to which cream within the cream tank is supplied under pressure by means of a gear pump after it has been intermingled with air during the passage thereof through the gear pump. The emulsifying barrel comprises a hollow cylindrical shell having an emulsifying chamber in which an elongated deflector assembly generally complemental in shape to the shape of the emulsifying chamber is accommodated. The deflector assembly is so designed as to provide a substantially labyrinth passage through which the mixture of air and cream flows in a substantially zig-zag manner. It is during the flow through the labyrinth passage that the air and the cream are agitated and intermingled to form an emulsion of air and cream which ultimately emerges outside of the machine in the form of a whipped cream from a dispensing spout coupled to the emulsifying barrel through a dispensing valve assembly.
The prior art whipped cream making machine is satisfactory in that whipped cream can be manufactured. However, it has been found that, since the extent to which the air and the cream are agitated and intermingled is insufficient, they tend to be insufficiently homogenized, the consequence of which is that not only does the resultant whipped cream occasionally bubble out from the dispensing spout during discharge thereof, but also the resultant whipped cream contains relatively large and irregular bubbles.
Moreover, in the prior art whipped cream making machine, since the dispensing valve assembly is so designed that, when a manipulatable handle is pivoted in one direction, a power control switch is turned on to energize an electric motor to drive the gear pump coupled to said motor through an endless belt on one hand and the dispensing valve is opened to permit the emulsion to be supplied towards the dispensing spout, there is the possibility that, even when the manipulatable handle is returned back to the original position with the power control switch turned off and with the dispensing valve closed, the emulsion within the emulsifying barrel is so highly pressurized by the continued rotation of the motor under the influence of an inertia force that a portion of the emulsion within the emulsifying barrel can be squeezed out through the dispensing valve to leak to the outside of the machine for a substantial period of time subsequent to the closure of the dispensing valve. This in turn results in waste of an expensive milk product.